1. Field of the Invention
The present invention relates to a test system, and more particularly, a test system including a test apparatus used for detecting faults which may occur in on-vehicle devices.
2. Description of the Related Art
Various types of on-vehicle ECUs (Electronic Control Units) have been used to control operation of on-vehicle devices such as engines, air conditioners, and others.
In order to achieve the control, an ECU is configured to communicate with various sensors and actuators. Thus, the ECU should have the capability of processing various data from and to the sensors and actuators. In some cases, a plurality of ECUs mounted on the same vehicle are electrically and communicably connected to each other via a vehicle LAN (Local Area Network) and communication IDs (identifications) are assigned to the ECUs respectively.
When an inspection is needed to detect a fault which may occur in the ECU, a test system dedicated to the inspection may be used. Specifically, Japanese Patent Application Laid-open Publication No. 2007-38921 discloses one type of test system, which is, for instance, an external tool which can be connected to the ECU via the vehicle LAN when being necessary. The external tool issues a command to the ECU so that the command allows the ECU to inspect the fault and to collect information concerning the fault, whereby the inspection can be conducted from outside the vehicle.
In recent years, the number of ECUs incorporated in electric control systems mounted on the same vehicle has increased with a rise in sophistication and high-function required control the behavior of the vehicle. This trend is continuing, and it is expected that the number of ECUs necessary in the same vehicle will increase in the future.
However, the space inside a vehicle is usually limited, thus, limiting the number of ECUs mountable in the vehicle. Of course, increasing the number of ECUs results in an increase in the vehicle weight and power consumption. This also limits the number of ECUs for each vehicle. For this reason, there has been known an alternative technique that two or more of all the ECUs are combined into a single ECU. Hereinafter, this ECU will be referred to as an integrated ECU in the present application.
Since the integrated ECU is communicably connected to other ECUs via a vehicle LAN similarly to the ECUs used before the integration, it is necessary to assign a communication ID to the integrated ECU. For instance, a new communication ID can be assigned to the integrated ECU. However, since it is usual that the ECUs include various types of ECUs with different specifications, the design has to consider many combinations of the communication IDs when ECUs are integrated.
Therefore, a lack of communication IDs which can be used for the assignment is likely to occur. In addition, when a new communication ID is assigned to the integrated ECU, it is required to strictly manage the assignment of the communication IDs to prevent communication IDs from being duplicated between the integrated ECU and another integrated ECU, which may also be arranged in the same vehicle. Accordingly, managing the assignment of the communication IDs will exert a significant burden on designers when integrating ECUs.
In this regard, to assign the communication ID for the integrated ECU, using a plurality of communication IDs being used by a plurality of ECUs which are being integrated to the integrated ECU, is proposed. As a result, problems such as lacking an amount of communication IDs and the duplication of the communication IDs used for the integrated ECUs can be avoided. Also, other ECUs trying to communicate with the ECUs being integrated (i.e., target ECU being integrated) can communicate with the individual ECU in the same way (i.e., communication IDs) as before the integration. In this way, the other ECU can communicate with the integrated ECU as the same way as before the integration. As a result, when the integration is performed, it is not required to renew the programs which are stored in the ECUs being not integrated.
However, according to the test system which is adapted to the above-described proposal, the test system has to order both of the integrated ECU and the individual ECU (i.e., target ECU being integrated) to be inspected as well as the other ECUs being communicate with the integrated ECU. Accordingly, when the test system is processing the inspection to the integrated ECU, despite that the number of ECU to be inspected is one, it is necessary to order the ECU to be inspected for multiple times. Therefore, the load of the processing in the test system increases.